The invention relates to a motor vehicle seat having a seat part and a backrest part as well as to an operating process for such a motor vehicle seat.
In the event of rear impact motor vehicle accidents, there is the risk that, as the result of the impact, occupants may slide up along the backrest part of their vehicle seat. The sliding-up will occur because, in the case of a rear impact, the backrest will bend toward the rear and will therefore form a slope.
In the event of a rear impact motor vehicle accident, an occupant is pushed so far upwards that his seat is virtually pushed through under him and such that his head strikes against the vehicle ceiling or is at least pushed beyond the headrest so that the latter no longer offers support. The consequences are serious head and/or spinal column injuries which may even be lethal. Currently, there is no effective protection in this respect.
It is therefore an object of the invention to provide a motor vehicle seat and an operating process therefor in order to better protect an occupant.
According to the invention, this is achieved by means of a motor vehicle seat as well as by means of an operating process for a motor vehicle seat. Preferred and advantageous further developments of the invention are described herein.
In the case of the motor vehicle seat according to the invention which has a seat part, a backrest part and protection devices, the protection devices contain a backrest adjusting device which can be released in the event of a rear impact and, after its release, controls the backrest part such that the latter counteracts an occupant's sliding-up along the backrest part because of the rear impact. In particular, the backrest part is adjusted to be as straight as possible and therefore counteracts the bending-back of the backrest part because of the rear impact.
The backrest part, which in the event of a rear impact, normally becomes a slope, can be stabilized by means of the seat adjusting device according to the invention.
According to a preferred further development of the invention, it is provided in the case of a motor vehicle seat that the backrest adjusting device contains release devices which either do or do not release the control of the backrest as a function of the force and/or the type of the rear impact and of the occupant's weight on the motor vehicle seat. The release devices preferably contain a load limiting device coupled to the backrest part.
The invention can be implemented particularly advantageously by means of a motor vehicle seat in the case of which the backrest part has a buttocks end which faces the seat part and a shoulder end which faces away from the seat part, and in the case of which the backrest adjusting device, after its release, acts toward a swivelling of the buttocks end and the shoulder end of the backrest part relative to one another such that, with respect to the respective position before the rear impact, the buttocks end can be adjusted toward the rear impact and/or the shoulder end can be adjusted away from the rear impact. According to a preferred further development thereof, it is provided that the backrest adjusting device is designed such that, after its release, it causes an adjustment of the backrest part from the seat part in the upward direction. By means of these designs, the effect of the invention is implemented in a particularly simple and good manner.
In the case of the above-explained preferred and advantageous embodiments of the vehicle seat, an implementation is permitted in that the backrest part is connected with the seat part on both sides of the motor vehicle seat by way of one holder respectively, and in that the backrest adjusting device contains forced control which acts between the seat part and the holders of the backrest part.
Preferably, the forced control on both sides of the vehicle seat contains one forward and one rearward lever, respectively, which are in each case rotatably disposed on the seat part by means of their lower ends and on the corresponding holder by means of their upper ends, and the rearward levers of which, being closer to the vehicle rear, are longer than the forward levers. In this embodiment, when the backrest adjusting device is not released, the forward and rearward levers extend in the direction away from the vehicle rear diagonally upward and at least essentially in parallel to one another. Furthermore, when the backrest adjusting device is released, the upper ends of the forward and rearward levers can be adjusted in the direction of the rear impact. This advantageously permits a solid and effective adjustment of the backrest part.
It is also particularly preferable for the seat adjusting device of the motor vehicle seat according to the invention to contain driving devices which at least promote or cause an action upon the backrest part after the release of the backrest adjusting device so that the backrest part counteracts an occupant's sliding-up as the result of the rear impact. Thus, the backrest part can be adjusted in a rapid and reliable manner. The driving devices are preferably coupled with the forced control. As an alternative or in addition, the driving devices may contain at least one pyrotechnical adjusting cylinder. Such pyrotechnical adjusting cylinders may be provided on both sides of the motor vehicle seat. However, it may be sufficient for a pyrotechnical adjusting cylinder to be used on one side of the motor vehicle seat, each pyrotechnical adjusting cylinder preferably being operatively coupled, on the one side, in a stationary manner on the seat part and, on the other side, on the upper end of the rearward lever.
Instead of using an additional pyrotechnical adjusting cylinder as a driving device, a pyrotechnical adjusting cylinder may also be used which is part of a side air bag system accommodated in the motor vehicle seat. Such an adjusting cylinder is designed for, on the one hand, pulling a side air bag out of its accommodation space into an operative position. This is done by means of a tension cable which is coupled on one side in the area of the shoulder end of the backrest part and on the other side with the adjusting cylinder which, after a triggering of the side air bag system, tensions the tension cable toward the forward free end of the seat part in order to, on the other hand, act upon the backrest part by the tensioning of the tension cable after the release of the backrest adjusting device so that the backrest part counteracts an occupant's sliding-up as the result of the rear impact. Further details concerning the development of suitable side air bag systems are disclosed in German Patent Applications 197 38 728.4 and 198 45 992.0, the latter being based on German Utility Model Application 297 17 795.8, as well as the analogous U.S. patent applications with the Ser. No. 09/017,858, with the title "AIR BAG DEVICE IN A VEHICLE AND METHOD FOR ACTIVATING AN AIR BAG DEVICE", filed on Feb. 3, 1998, and Ser. No. 09/165,744 with the title "SIDE AIR BAG DEVICE, METHOD FOR OPERATION THEREOF AND VEHICLE SEAT THEREWITH, filed on Oct. 6, 1998, which all originate from the present inventor and applicant, and to whose contents reference is made hereby concerning the characteristics for developing the side air bag system, if these characteristics can be used in connection with the backrest part adjustment according to the present invention. For avoiding comprehensive citations, the corresponding characteristics and further developments are included completely in the present documents to the extent of the reference.
In connection with the driving devices, it is also preferred for these driving devices, for the purpose of their activation, to be coupled with sensor devices for detecting a rear impact. In this case, it may advantageously be provided that the sensor devices are coupled with the release devices in order to trigger the driving devices only when the backrest adjusting devices are released.
Within the scope of another preferred embodiment of the invention, the backrest adjusting device, which can be released in the event of a rear impact, may contain preadjusting devices which are coupled with sensor devices for detecting an imminent rear impact and, after the release of the backrest adjusting device, adjust the backrest part such that the latter counteracts an occupant's sliding-up because of the rear impact. This is preferably achieved in that the preadjusting devices contain an electric or hydraulic drive which is coupled with a forced control of the backrest part, that the backrest part has a buttocks end facing the seat part and a shoulder end facing away from the seat part, and that the forced control after the release of the backrest adjusting device by means of the electric or hydraulic drive causes a swivelling of the buttocks end and of the shoulder end of the backrest part relative to one another such that, with respect to the respective position before the effect of the preadjusting devices, the buttocks end can be adjusted toward the rear impact and/or the shoulder end can be adjusted away from the rear impact. Another preferable further development provides that the forced control after the release of the backrest adjusting device by means of the electric or hydraulic drive causes an adjusting of the backrest part from the seat part in the upward direction.
It is also advantageous for the backrest adjusting device to contain absolute and/or relative limiting devices for limiting the effect and/or movement of the control of the backrest part. As a result, it is avoided that the adjustment of the backrest part is too wide.
It is also advantageous for the release and/or the activation of the backrest part adjustment to be coupled with the triggering of additional safety devices. The combination of the backrest part adjustment with a side air bag or thorax air bag was explained in connection with an above-mentioned preferred embodiment of the invention, in which case not only the combination of the effects is utilized but also that of the functions. In this case, a combined triggering mechanism is also within the scope of the present invention, with respect to which reference is made to the above-indicated older applications, and by means of this reference, the contents of the above-mentioned older applications are included to their full extents in the present documents in order to avoid comprehensive citations. An adjustable headrest can also be triggered together with the backrest part adjustment. In particular, like the backrest part adjustment according to the present invention, the headrest adjustment can also take place preventively before a rear impact. Another combination variant of the backrest part adjustment according to the invention takes place together with a headrest air bag and/or together with belt tightening devices whose triggering can be utilized for triggering the backrest part adjustment of the present invention, or the activation of this backrest part adjustment may trigger a headrest air bag and/or belt tightening devices. It is also possible that several safety devices are activated or triggered in parallel. In particular, the same sensor devices can be used for the triggering of the backrest part adjustment and of additional safety devices. Preferably, the movement of the backrest part adjustment can, for example, be used for the triggering and/or causing of headrest adjustment.
With respect to details concerning the techniques to be combined by means of the present invention, reference is made to the older German Patent Applications 196 41 224.2, 197 07 998.9, 197 38 727.6 and 198 44 413.3 as well as the older U.S. patent applications with the Ser. No. 08/946.579, with the title "DRIVING DEVICE, ESPECIALLY FOR TIGHTENING A SAFETY BELT IN A MOTOR VEHICLE", filed on Oct. 7, 1997, and Ser. No. 09/031,914, with the title "VEHICLE SEAT", filed on Feb. 27, 1998. All these older applications originate from the inventor and the applicant of the present application and, in order to avoid comprehensive citations, are included with their complete contents in the present documents, if the characteristics and embodiments which are indicated in the older applications can be combined with the present invention.
The invention also contains an operating process for a motor vehicle seat having a seat part and a backrest part. In the event of a rear impact, the backrest part is controlled into a protective position so that it counteracts an occupant's sliding-up along the backrest part as the result of the rear impact.
As a preferred further development, it is possible that, when the motor vehicle seat is mounted in the driving direction, in the event of a rear impact, the backrest part is adjusted on its buttocks end toward the rear impact and/or, on its shoulder end, away from the rear impact into a protective position with respect to the adjustment of the backrest part before the rear impact. This process can be further developed in that, in the event of a rear impact, the backrest part is adjusted from the seat part additionally in the upward direction into a protective position with respect to the adjustment of the backrest part before the rear impact.
Preferably, in the case of the process according to the present invention, the achieving of the protective position of the backrest part is at least promoted or caused by means of sensor devices for detecting a rear impact and driving devices coupled therewith. As an alternative or in addition, the backrest part can be adjusted into the protective position before an imminent rear impact by means of sensor devices for detecting an imminent rear impact and preadjusting devices coupled therewith.
Additional advantageous further developments of the invention are found in the embodiments which will be described in the following in the manner of examples with reference to the drawings.